How bright should my CAT get?

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barrettdp

Member
Dec 20, 2008
61
NE Georgia
On our Defiant the top of the CAT is visible and has a light glow during operation. Earlier this week I was burning some oak pallet wood and noticed the CAT chamber started glowing EXTREMELY bright and had visible flames coming from the top of the bottom fireback (this is where the secondary air comes in). I also noticed a much different noise coming from the back of the stove sounding like rushing air that I had never heard before, and increased temp from the rear of the stove. Temp per magnetic griddle was no more than 500*.

I panicked thinking the actual CAT chamber was having a meltdown, and hit it with the fire extinguisher. The next day I took the whole thing apart and could not find any problem what so ever, except the extinguisher goo caked up on everything.

After putting it back together I fired it back up with a very small load of the same wood and sure nuff it did it again.

Stove top griddle at about 500* per the magnetic gauge. I moved the gauge to a spot on the upper rear of the stove and the gauge started climbing very fast, but much to my surprise never got above 700*. I just watched it through the whole burn cycle. Noticed that if I get back puffing or reflame up in the primary chamber the glowing in the CAT chamber dies down until the flames die out again. I figure this is pretty normal. This is my first time burning pallet wood. It does not happen with any cord wood I have burned, only a light glow.

I made a video of the glowing CAT but due to lighting and what not it really does not do it justice. The chamber is glowing much brighter than the video looks. but I'll link it any ways. Here is also a pic of the temp gauge on the back of the stove at 700* as the griddle was no more than 500.

Here is also a pic of my CAT after the extinguisher had it's way with it. Surprisingly after I scraped it off as best I could it didn't seem to harm it.

I also learned that the $20 kitchen fire extinguishers are for SMALL fires and are completely empty in about 3-5 seconds!

And please ignore the background sound of the video. I was catching up on my Jesse Ventura Conspiracy Theory!


 

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Here is also a quote from the manual

The baffle is made of a special cast iron which can
withstand higher temperatures than most other parts of
your stove. It protects the catalytic element from direct
flame impingement, which can shorten the catalyst’s
life. Since the baffle is in the direct path of flame
between the firebox and the catalyst, it reaches higher
temperatures than other firebox parts, and it may glow
at times. If it does glow, you will see this directly
through the front doors. The glow is normal and does
not indicate a problem.
At times you may see a glow from the catalyst
shining through the ports of the baffle. This is also
normal and does not indicate a problem. The catalytic
element, located below and behind the baffle, can glow
at high temperatures. This is also normal. However, the
element can be active and operate properly without
glowing. The lack of a glow does not indicate that the
catalyst isn’t working. Note that the catalyst is mostlikely to glow at its higher temperatures, which it
reaches when the firebox is in its lower range - the
catalyst is an afterburner, and the more waste fuel there
is in the smoke, the hotter the catalyst gets.
 
I dunno..........don't own a Cat stove........so that disqualifies my remarks...........

However, that said...........if I saw melting stuff..........I think I'd back off (lol)

-Soupy1957
 
Soupy, there was no meltdown. The OP stated, "I panicked thinking the actual CAT chamber was having a meltdown." Thinking there might be one and having one is two different things.

Not sure if I'd have used a fire extinguisher or not but it does not sound to me like anything to be concerned with. For sure burning pallet wood will give you a super hot fire so bear that in mind when loading the stove. You stated this does not happen when burning cordwood but only when burning pallet wood. That gives you a good clue.

As for the glow of the cat, I did not see anything in the video that would cause me to get excited but instead, I'd probably smile knowing the cat was doing its job. Perhaps I am wrong, but I'd just go on burning but being careful to not put too much of that pallet wood in the stove.
 
That depends on its parentage. We have one that can open doors, another that holds a "conversation" with us, yet another that . . . . . .

Oh. that kind of cat. Never mind, then. :red: :)
 
WhitePine said:
That depends on its parentage. We have one that can open doors, another that holds a "conversation" with us, yet another that . . . . . .

Oh. that kind of cat. Never mind, then. :red: :)

My friend's cat would jump up and ring the doorbell when it wanted inside. :)
 
In our Encore CAT, we've seen that before. The Refractory box ABOVE the cat combustor may get to glowing (bright, like
the filament of a bulb) and we try to avoid it. It's caused by secondary combustion happening BEFORE the unburnt smoke gets into
the combustor. The fresh secondary air is indeed fed up the rear of the lower fireback and joins the smoke then its all sucked downward through the cat. As many times as we've seen the upper refractory box glow bright like that, it's never seemed to harm the
fragile spun ceramic of the refractory. The Encore has a "hood" covering the cat's intake port and we can't see the cat in operation.
If VC made a baffle to replace the hood (so we could view the cat) I'd buy one in a second.
 
Gark said:
In our Encore CAT, we've seen that before. The Refractory box ABOVE the cat combustor may get to glowing (bright, like
the filament of a bulb) and we try to avoid it. It's caused by secondary combustion happening BEFORE the unburnt smoke gets into
the combustor. The fresh secondary air is indeed fed up the rear of the lower fireback and joins the smoke then its all sucked downward through the cat. As many times as we've seen the upper refractory box glow bright like that, it's never seemed to harm the
fragile spun ceramic of the refractory. The Encore has a "hood" covering the cat's intake port and we can't see the cat in operation.
If VC made a baffle to replace the hood (so we could view the cat) I'd buy one in a second.


Thanks a bunch Gark. This is about what I figured was happening. Now that it's done it several times I'm fine with it. It's actually quite nice to look at as well.
 
Boozie said:
WhitePine said:
That depends on its parentage. We have one that can open doors, another that holds a "conversation" with us, yet another that . . . . . .

Oh. that kind of cat. Never mind, then. :red: :)

My friend's cat would jump up and ring the doorbell when it wanted inside. :)
 

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